Can't install "critical hot fix"

I’m running Scrivener 1.9.7.0 under Crossover Office. When I start Srivener I get a window urging me to install a “Critical Hot Fix” from October 10th. But every time I try to install this patch I get a “Fatal Error in Installer” message with the content “Called Tcl_Close on channel with refCount > 0”.

Anybody have any insight into what’s happening and how to fix it?